Organizations such as on-line retailers, Internet service providers, search providers, financial institutions, universities, and other computing-intensive organizations often conduct computer operations from large scale computing facilities. Such computing facilities house and accommodate a large amount of server, network, and computer equipment to process, store, and exchange data as needed to carry out an organization's operations. Typically, a computer room of a computing facility includes many computing racks, which may include server racks. Each computing rack, in turn, may include many computer systems, servers, associated computer equipment, etc.
Because the computer room of a computing facility may contain a large number of servers, a large amount of electrical power may be required to operate the facility. In addition, the electrical power is distributed to a large number of locations spread throughout the computer room (e.g., many racks spaced from one another, and many servers in each rack). Usually, a facility receives a power feed at a relatively high voltage. This power feed is stepped down to a lower voltage (e.g., 208V). A network of cabling, bus bars, power connectors, and power distribution units, is used to deliver the power at the lower voltage to numerous specific components in the facility.
Some data centers have limited redundancy in power systems. Some data centers have redundant systems but the redundant systems rely on non-redundant components to switch between the redundant systems. The down-time associated with power failures and maintenance of power systems in a data center may result in a significant loss in computing resources. In some critical systems such as hospital equipment and security systems, down-time may result in significant disruption and, in some cases, adversely affect health and safety.
In some systems, an automatic transfer switch (“ATS”) provides switching from a primary power system to a secondary (e.g., back-up) power system. In a typical system, the automatic transfer switch automatically switches a computing rack to the secondary system upon detecting a fault in the primary power. To maintain the computing equipment in continuous operation, the automatic transfer switch may need to make the transfer to a secondary power system rapidly (for example, within about 16 milliseconds).
Some data centers rely on a single ATS to switch between primary and secondary power systems. In some data centers an ATS may feed electrical power from a primary power system the majority of the time the ATS is in operation and infrequently swap to feed electrical power from a secondary power system.
As a result, ATSs may disproportionately fail when switching from a primary power system to a secondary power system, thereby causing a loss of electrical power to the loads supported by the ATS. In addition, in order to ensure ATSs are in good repair and likely to function when needed, periodic maintenance may be performed on ATSs. Such failures and maintenance may further require extended computing unit downtime and may require temporarily taking otherwise unrelated systems and components offline, thereby exacerbating costs.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to.